Modal Energy Analysis of Nearly Rectangular Rooms at Low Frequencies
This paper describes a method where the normal modes of a rectangular room are analysed as independent resonant systems with internal losses derived from the absorption properties of the room surfaces. Thus the resonance frequency, the bandwidth, and the decay rate of each normal mode can be calculated. A new method using a representative wave has been applied to calculate the decay rate of a normal mode. By adding the frequency responses of all normal modes up to a sufficiently high order the global frequency response below 200 Hz is found. The decay curve within a frequency band can be calculated by adding together the individual decay curves of the relevant modes. Typically the axial modes have longer reverberation times than tangential and oblique modes, and thus the total decay curve will not be a perfectly straight line. The effect of angled walls or scattering treatment of surfaces is modelled in terms of modal energy analysis, the most important result being that sound energy is transferred from the powerful axial modes to other modes with less energy, and thus leading to a shorter reverberation time. A new theoretical model for energy losses of axial modes due the scattering or angled walls is presented. The presented model using modal energy analysis is suggested as a tool for the analysis and design of small music practice rooms and recording studios.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: November 1, 2015
More about this publication?
- Acta Acustica united with Acustica, published together with the European Acoustics Association (EAA), is an international, peer-reviewed journal on acoustics. It publishes original articles on all subjects in the field of acoustics, such as general linear acoustics, nonlinear acoustics, macrosonics, flow acoustics, atmospheric sound, underwater sound, ultrasonics, physical acoustics, structural acoustics, noise control, active control, environmental noise, building acoustics, room acoustics, acoustic materials, acoustic signal processing, computational and numerical acoustics, hearing, audiology and psychoacoustics, speech, musical acoustics, electroacoustics, auditory quality of systems. It reports on original scientific research in acoustics and on engineering applications. The journal considers scientific papers, technical and applied papers, book reviews, short communications, doctoral thesis abstracts, etc. In irregular intervals also special issues and review articles are published.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Information for Advertisers
- Online User License
- Ingenta Connect is not responsible for the content or availability of external websites